Automatic starting mechanism for internal combustion engines



' Nov. 20, 1934.

D. L. WERTZ 1,981,209

AUTOMATIC STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed April 29. 1931 s 1 g :3 0 a "11' Q O o \l\ NIH Hm INVENTOR Dd1l161 L.Wer1% Mud Patented Nov. 20, 1934 UNITED STATES AUTOMATIC STARTING MECHANISM FOB INTERNAL COMBUSTION ENGINES Daniel L. Wertz, Elmira, N. Y., assignmto Eclipse Machine Company, Elmira, N. Y., a corporation of New York Application Aprll 29, 1931, Serial No. 533,620

4Claima.

This invention relates to automatic starting mechanism for internal combustion engines and more particularly to a device for protecting the starting mechanism and conserving the source of electrical energy in case the engine fails to start after the starting motor circuit has been'energized for a predetermined length of time.

It is an object of the present invention to provide an automatic starting mechanism embodying novel means for causing the starting circuit to be opened after the same has been energized for a predetermined length of time without having accomplished seli-energization of the internal combustion engine.

Another object is to provide such a device including a circuit for controlling the starting circuit in which overloading the starting circuit causes the control circuit to be broken and a holding circuit to be established for keeping the control circuit open until the operator opens the holding circuit.

A further object is to provide such a device in which the holding circuit is arranged to be controlled by the ignition switch of the internal combustion engine so that opening and closing the ignition switch resets the automatic starting mechanism for normal operation.

Further objects and advantages will be apparent to those skilled in this art from the following description taken in connection with the accompanying drawing in which the figure is a semidiagrammatic illustration of a preferred embodiment of the invention, the automatic starting switch elements being shown in elevation and partly in vertical section.

motor circuit including a battery 10, one terminal ot which is grounded at 11 and the other terminal of which is connected by a lead 12 to an automatic starting mechanism comprising a starting switch having a stationary element 13 connected to the lead 12, a second stationary element 14 and a movable insulated bridging element 16. The stationary element 14 is connected through a lead '17 to a single turn coil 18 which latter is connected by a. lead 19 to a conductor 21 which in turn is connected by a lead 22 to the starting :ntor SM, grounded at 23 to complete the starting circuit.

The movable element 16 of the starter switch is mounted by suitable insulating means on a magnetic plunger 24 which is normally maintained in its upper position by means such as a spring 26 but which may be drawn down to close the starting switch by a solenoid 2'1. Said solenoid is included in a control circuit comprising the battery 10, lead 12, lead 15, manual switch 28 which may as indicated be the ignition switch of the internal combustion engine) lead 29, heatresponsive spring strip 31, contact 32 mounted thereon, fixed contact 33, lead 34, solenoid 27, lead 36, insulated'bracket 3'7 and relay plunger 38 which is grounded as indicated at 39.

The relay plunger- 38 is normally retained in contact with the insulated bracket 3'7 as illustrated by suitable means such as a spring 41 whereby closure of the manual switch 28 by the operator will cause energization of the control circuit to close the starting switch 13, 16, 14. A voltage coil 42 and a generator coil 43 are arranged to surround the lower part of the relay plunger 38 and when energized attract the same downwardly to break the contact between said plunger and the bracket 3'! and thereby open the control circuit. The voltage coil 42 is connected at one end by a lead 44 to the motor circuit lead 19, and is grounded at its other end at 46. Generator coil 43 is connected at one end by a lead 47 to the generator G and is also grounded at its other end at 46.

A heating element 48 is arranged to surround the heat-responsive member 31 being suitably insulated therefrom and being arranged as indicated in shunt with the conductor 21 of the starting motor circuit whereby said heating element is energized by an aliquot portion of the starting current which is measured by the inverse ratio of the resistance or said heating element and conductor.

The heat-responsive member 31 is so arranged that a rise in temperature therein causes deflection thereof in a direction to move contact 32 away from fixed contact 33 and thus break the control circuit. A contact and armature member 49 is mounted on the free end of the heat- In the drawing there is. illustrated a starting;

responsive member 31 adjacent one pole of an electro-magnet 51, the, coil 52 of which is connected at one end to its core 53 as indicated at 54, and the other end of which is grounded as at 56. The core 53 of the electro-magnet 51 is so located that deflection of the heat-responsive member 31 causes contact 49 to engage the core and thus complete a circuit throughthe coil 52 to the ground at 56. The consequent energization of the electro-magnet holds the contact 49 in engagement with the core 53 until the holding circuit is broken by opening the ignition switch 28. In' the normal operation of the device, closure of the ignition switch 28 closes the control circuit, causing the solenoid 27 to close the starting switch 13, 16, 14, thus completing the starting circuit whereby the starting motor is caused to crank the engine. During this time, the voltage coil 42 is energized by reason of its connection to the starting circuit lead 19, but the heavy current traversing the single turn coil 18 holds the plunger 38 in its upper position. This holding effect is preferably controlled by means such as an adjustable magnetizable pole piece57 mounted within the single turn coil 18 adjacent the end of relay plunger 38. I

If the engine becomes self-operative after a reasonable amount of cranking, the load on the starting motor is thereupon relieved and the consequent reduction of the current through the single turn coil 18 together with the increase of voltage drop through the voltage coil 42 enables the latter to overcome the efiect of the single turn coil 18 and the spring 41 and draw the plunger 38 downward into engagement with a fixed pole piece 58, breaking the contact between said plunger and the bracket 37. The consequent opening of the control circuit causes the deenergization of the solenoid 2'7 thus releasing the starting switch plunger 24 whereupon the spring 26 operates to open the starting switch. When the starting switch opens, the voltage coil 42 is disconnected from the battery '10. The relay plunger 38 is not immediately released however, since the voltage coil 42 is traversed by a slight amount of current generated by the starting motor spinning by momentum in its residual field, this current being sufiicient to hold the plunger 38 against its pole piece 58 until the starting motor has come substantially to rest. Before the voltage coil 42 becomes entirely deenergized, the generator G which'is driven from the engine, builds up sufiicient voltage to energize the generator coil 43 and retain the relay plunger 38 in its lower position, thus holding the control circuit open as long as the engine is self-operative.

If the engine should stall for any reason, the generator coil 43 becomes deenergized and the spring 41 raises the relay plunger 38, thus closing the control circuit and the starting operation is repeated. It will be understood that reclosing the starting switch may, if desired, be retarded by suitable means such as a cup washer 59 arranged on the plunger 24 and adapted to cooperate with the core of the solenoid 27 to form a dashpot therewith.

When the engine becomes self-operative with a normal amount of cranking, the heat-responsive member 31 does not become sufliciently heated to break the contacts 32, 33, and the starting operation takes place as above described. If, however,

the engine should fail to start within a predetermined time owing to improper functional conditions of the engine, or if the starting gearing should be locked for any reason, the heat responsive member 31 will become sufliciently heated to move contact 32 outv of engagement with contact 33 and at substantially the same time move contact'49 into engagement with the core engine, it is only necessary forhim to open the ous changes may be made in the proportions and arrangements of the parts here shown without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an automatic starting mechanism for internal combustion engines, a starting circuit including a source of energy, a starting motor and a starting switch for controlling said motor, a control circuit for said starting switch including electro-magnetic actuating means therefor, a manual switch and an automatic switch; a holding circuit for said automatic switch including means for retaining the automatic switch in open position; and means responsive to overload of said starting circuit for opening said control circuit and closingsaid holding circuit, said manual switch being included in both the control circuit and the holding circuit whereby opening of said manual switch breaks both control and holding circuits.

2. In an automatic starting mechanism for internal combustion engines, a starting circuit including a source of energy, a starting motor and a starting switch for controlling said motor, a control circuit for said starting switch including electro-magnetic actuating means therefor, a manual switch and a pair of normally closed contacts; a heat-responsive member adapted when heated to open said contacts, a heating element therefor arranged to be heated by current traversing the starting circuit; and a holding circuit for said contacts including electro-magnetic means for holding said contacts open and a second pair of contacts adapted to be closed by a rise in temperature of said heat-responsive member.

3. In an automatic starting mechanism for internal combustion engines, a starting circuit including a source of energy, a starting motor and a starting switch for controlling said motor, a control circuit for said starting switch including electro-magnetic actuating means therefor, a manual switch and a pair of normally closed contacts; a heat-responsive member adapted when heated to open said contacts, a heating element therefor arranged to be heated by. current traversing the starting circuit, and a holding circuit for said contacts including electro-magnetic means for holding said contacts open and a second pair of contacts adapted to be closed'by a rise in temperature of said heat-responsive member, said manual switch being included in the holding circuit whereby opening of said manual switch breaks said holding circuit.

4. In automatic starting mechanism for internal combustion engines, an ignition circuit including an ignition switch, a starting circuit including a main conducting element of large load capacity and a shunt conducting element of relatively small load capacity; a control circuit including said ignition switch, controlling elements for the starting circuit, a thermostatic conducting element and contacts controlled thereby to break the control circuit; and a holding circuit including said ignition switch, contacts closed by said thermostatic element and means energized thereby for holding the latter contacts closed and the first mentioned contacts open; said shunt conducting element being constructed and proportioned to be heated by the passage of cranking current therethrough, and being thermally connected to the thermostatic element.

DANIEL L. WERTZ. 

